Sorry, I accidentally sent that email half-finished.

On Sun, Aug 23, 2015 at 12:20 PM, Pip Cet <pipcet@gmail.com> wrote:
>>> I'm not a hundred percent certain; from reading the thread, I think
>>> it's the former: the window is in full-screen mode and starts
>>> shrinking. I've installed KWin but have been unable to produce buggy
>>> behavior, so far, without the workaround in gtkutil.c.
>>
>> I attach a patch that should handle the case where we want to switch
>> from a non-fullscreen to a fullscreen frame.  Please try it.

That patch has no effect, but that's consistent with my understanding
of the situation; it might have an effect on users of the buggy KWin
version.

I've attached a patch that combines your patch with the minor fixes I
suggested in the previous email. It appears to work here.